commit 28a5dc7fc587a2737cc6cc0bfa13129925cda133
author Fangrui Song <maskray@google.com> Wed Nov 13 13:10:15 2019 -0800
committer Fangrui Song <maskray@google.com> Fri Nov 15 10:05:36 2019 -0800
tree 7c529ae09810a55155936e78b8204dcea9c6b1bc
parent 8bcd01f48ac8417a07ff941bdbfc422a55a4bc8d

[llvm-objcopy][MachO] Implement --redefine-sym and --redefine-syms

Similar to D46029 (ELF) and D70036 (COFF), but for MachO.
Note, when --strip-symbol (not implemented for MachO) is also specified,
--redefine-sym executes before --strip-symbol.

Reviewed By: jhenderson, seiya

Differential Revision: https://reviews.llvm.org/D70212

llvm/tools/llvm-objcopy/MachO/MachOObjcopy.cpp

diff --git a/llvm/tools/llvm-objcopy/MachO/MachOObjcopy.cpp b/llvm/tools/llvm-objcopy/MachO/MachOObjcopy.cpp
index cad9666..dbdd44c 100644
--- a/llvm/tools/llvm-objcopy/MachO/MachOObjcopy.cpp
+++ b/llvm/tools/llvm-objcopy/MachO/MachOObjcopy.cpp
@@ -56,7 +56,13 @@
       (*ISE.Symbol)->Referenced = true;
 }
 
-static void removeSymbols(const CopyConfig &Config, Object &Obj) {
+static void updateAndRemoveSymbols(const CopyConfig &Config, Object &Obj) {
+  for (SymbolEntry &Sym : Obj.SymTable) {
+    auto I = Config.SymbolsToRename.find(Sym.Name);
+    if (I != Config.SymbolsToRename.end())
+      Sym.Name = I->getValue();
+  }
+
   auto RemovePred = [Config](const std::unique_ptr<SymbolEntry> &N) {
     if (N->Referenced)
       return false;
@@ -75,7 +81,7 @@
       Config.NewSymbolVisibility || !Config.SymbolsToGlobalize.empty() ||
       !Config.SymbolsToKeep.empty() || !Config.SymbolsToLocalize.empty() ||
       !Config.SymbolsToWeaken.empty() || !Config.SymbolsToKeepGlobal.empty() ||
-      !Config.SectionsToRename.empty() || !Config.SymbolsToRename.empty() ||
+      !Config.SectionsToRename.empty() ||
       !Config.UnneededSymbolsToRemove.empty() ||
       !Config.SetSectionAlignment.empty() || !Config.SetSectionFlags.empty() ||
       Config.ExtractDWO || Config.KeepFileSymbols || Config.LocalizeHidden ||
@@ -95,7 +101,7 @@
   if (Config.StripAll)
     markSymbols(Config, Obj);
 
-  removeSymbols(Config, Obj);
+  updateAndRemoveSymbols(Config, Obj);
 
   if (Config.StripAll)
     for (LoadCommand &LC : Obj.LoadCommands)

llvm/tools/llvm-objcopy/MachO/Object.h

diff --git a/llvm/tools/llvm-objcopy/MachO/Object.h b/llvm/tools/llvm-objcopy/MachO/Object.h
index 8642ce3..fb57637 100644
--- a/llvm/tools/llvm-objcopy/MachO/Object.h
+++ b/llvm/tools/llvm-objcopy/MachO/Object.h
@@ -110,6 +110,12 @@
 struct SymbolTable {
   std::vector<std::unique_ptr<SymbolEntry>> Symbols;
 
+  using iterator = pointee_iterator<
+      std::vector<std::unique_ptr<SymbolEntry>>::const_iterator>;
+
+  iterator begin() const { return iterator(Symbols.begin()); }
+  iterator end() const { return iterator(Symbols.end()); }
+
   const SymbolEntry *getSymbolByIndex(uint32_t Index) const;
   SymbolEntry *getSymbolByIndex(uint32_t Index);
   void removeSymbols(